LaserBeamsBarrel Class Reference

#include <LaserBeamsBarrel.h>

Inheritance diagram for LaserBeamsBarrel:

Public Member Functions
void	GeneratePrimaries (G4Event *myEvent) override
	shoot optical photons into the detector at the beginning of an event More...
	LaserBeamsBarrel ()
	default constructor More...
	LaserBeamsBarrel (G4int nPhotonsInGun, G4int nPhotonsInBeam, G4double PhotonEnergy)
	constructor More...
void	setOptPhotonPolar (G4double Angle)
	set the polarisation of the photons More...
	~LaserBeamsBarrel () override
	destructor More...

Private Attributes
CLHEP::DRand48Engine *	theDRand48Engine
G4int	thenParticle
G4int	thenParticleInGun
G4ParticleGun *	theParticleGun
G4double	thePhotonEnergy

Detailed Description

Define the LaserBeams which connect both TECs and TIB and TOB with eachother

Date

2007/06/11 14:44:28

Revision

1.3

Author

Maarten Thomas

Definition at line 21 of file LaserBeamsBarrel.h.

Constructor & Destructor Documentation

LaserBeamsBarrel() [1/2]

LaserBeamsBarrel::LaserBeamsBarrel

(

)

default constructor

Definition at line 21 of file LaserBeamsBarrel.cc.

References EcalCondDBWriter_cfi::Energy.

                                   : theParticleGun(nullptr), theDRand48Engine(nullptr) {
  G4int nPhotonsGun = 1;
  G4int nPhotonsBeam = 1;
  G4double Energy = 1.15 * eV;
  // call constructor with options
  LaserBeamsBarrel(nPhotonsGun, nPhotonsBeam, Energy);
}

LaserBeamsBarrel() [2/2]

LaserBeamsBarrel::LaserBeamsBarrel	(	G4int	nPhotonsInGun,
		G4int	nPhotonsInBeam,
		G4double	PhotonEnergy
	)

constructor

Definition at line 29 of file LaserBeamsBarrel.cc.

References setOptPhotonPolar(), theDRand48Engine, thenParticle, thenParticleInGun, theParticleGun, and thePhotonEnergy.

    : thenParticleInGun(0), thenParticle(0), thePhotonEnergy(0), theParticleGun(), theDRand48Engine() {
  /* *********************************************************************** */
  /*  initialize and configure the particle gun                              */
  /* *********************************************************************** */

  // the Photon energy
  thePhotonEnergy = PhotonEnergy;

  // number of particles in the Laser beam
  thenParticleInGun = nPhotonsInGun;

  // number of particles in one beam. ATTENTION: each beam contains
  // nParticleInGun with the same startpoint and direction. nParticle gives the
  // number of particles in the beam with a different startpoint. They are used
  // to simulate the gaussian beamprofile of the Laser Beams.
  thenParticle = nPhotonsInBeam;

  // create the particle gun
  theParticleGun = new G4ParticleGun(thenParticleInGun);

  // default kinematics
  G4ParticleTable *theParticleTable = G4ParticleTable::GetParticleTable();
  G4ParticleDefinition *theOpticalPhoton = theParticleTable->FindParticle("opticalphoton");

  theParticleGun->SetParticleDefinition(theOpticalPhoton);
  theParticleGun->SetParticleTime(0.0 * ns);
  theParticleGun->SetParticlePosition(G4ThreeVector(-500.0 * cm, 0.0 * cm, 0.0 * cm));
  theParticleGun->SetParticleMomentumDirection(G4ThreeVector(5.0, 3.0, 0.0));
  theParticleGun->SetParticleEnergy(10.0 * keV);
  setOptPhotonPolar(90.0);

  // initialize the random number engine
  theDRand48Engine = new CLHEP::DRand48Engine();
}

~LaserBeamsBarrel()

LaserBeamsBarrel::~LaserBeamsBarrel ( )

override

destructor

Definition at line 65 of file LaserBeamsBarrel.cc.

References theDRand48Engine, and theParticleGun.

                                    {
  if (theParticleGun != nullptr) {
    delete theParticleGun;
  }
  if (theDRand48Engine != nullptr) {
    delete theDRand48Engine;
  }
}

Member Function Documentation

GeneratePrimaries()

void LaserBeamsBarrel::GeneratePrimaries ( G4Event *  myEvent )

override

shoot optical photons into the detector at the beginning of an event

Definition at line 74 of file LaserBeamsBarrel.cc.

References funct::cos(), M_PI, ecalTB2006H4_GenSimDigiReco_cfg::myEvent, edm::RandomNumberGenerator::mySeed(), fileCollector::seed, setOptPhotonPolar(), funct::sin(), theDRand48Engine, thenParticle, theParticleGun, and thePhotonEnergy.

Referenced by LaserPrimaryGeneratorAction::GeneratePrimaries().

                                                         {
  // this function is called at the beginning of an Event in
  // LaserAlignment::upDate(const BeginOfEvent * myEvent)

  // use the random number generator service of the framework
  edm::Service<edm::RandomNumberGenerator> rng;
  unsigned int seed = rng->mySeed();

  // set the seed
  theDRand48Engine->setSeed(seed);

  // number of LaserBeams
  const G4int nLaserBeams = 8;

  // z position of the Laserdiodes (value from design drawings)
  G4double LaserPositionZ = 1137.0 * mm;

  // Radius of the Laser ring
  G4double LaserRingRadius = 564.0 * mm;

  // phi positions of the Laserdiodes (from CMS Note 2001/053 or from
  // http://abbaneo.home.cern.ch/abbaneo/cms/layout)
  G4double LaserPhi[nLaserBeams] = {G4double(7.0 / 112.0) * G4double(2.0 * M_PI),
                                    G4double(23.0 / 112.0) * G4double(2.0 * M_PI),
                                    G4double(33.0 / 112.0) * G4double(2.0 * M_PI),
                                    G4double(49.0 / 112.0) * G4double(2.0 * M_PI),
                                    G4double(65.0 / 112.0) * G4double(2.0 * M_PI),
                                    G4double(77.0 / 112.0) * G4double(2.0 * M_PI),
                                    G4double(93.0 / 112.0) * G4double(2.0 * M_PI),
                                    G4double(103.0 / 112.0) * G4double(2.0 * M_PI)};

  // width of the LaserBeams
  G4double LaserBeamSigmaX = 0.5 * mm;
  G4double LaserBeamSigmaY = 0.5 * mm;

  // get the definition of the optical photon
  G4ParticleTable *theParticleTable = G4ParticleTable::GetParticleTable();
  G4ParticleDefinition *theOpticalPhoton = theParticleTable->FindParticle("opticalphoton");

  // loop over the LaserBeams
  for (int theBeam = 0; theBeam < nLaserBeams; theBeam++) {
    // code for forward and backward beam
    // calculate x and y position of the current laser diode
    G4double LaserPositionX = cos(LaserPhi[theBeam]) * LaserRingRadius;
    G4double LaserPositionY = sin(LaserPhi[theBeam]) * LaserRingRadius;

    // loop over all the particles in one beam
    for (int theParticle = 0; theParticle < thenParticle; theParticle++) {
      // get randomnumbers  and calculate the position
      CLHEP::RandGaussQ aGaussObjX(*theDRand48Engine, LaserPositionX, LaserBeamSigmaX);
      CLHEP::RandGaussQ aGaussObjY(*theDRand48Engine, LaserPositionY, LaserBeamSigmaY);

      G4double theXPosition = aGaussObjX.fire();
      G4double theYPosition = aGaussObjY.fire();
      G4double theZPosition = LaserPositionZ;

      // set the properties of the newly created particle
      theParticleGun->SetParticleDefinition(theOpticalPhoton);
      theParticleGun->SetParticleTime(0.0 * ns);
      theParticleGun->SetParticlePosition(G4ThreeVector(theXPosition, theYPosition, theZPosition));
      theParticleGun->SetParticleEnergy(thePhotonEnergy);

      // loop over both directions of the beam
      for (int theDirection = 0; theDirection < 2; theDirection++) {
        // shoot in both beam directions ...
        if (theDirection == 0)  // shoot in forward direction (+z)
        {
          theParticleGun->SetParticleMomentumDirection(G4ThreeVector(0.0, 0.0, 1.0));
          // set the polarization
          setOptPhotonPolar(90.0);
          // generate the particle
          theParticleGun->GeneratePrimaryVertex(myEvent);
        } else if (theDirection == 1)  // shoot in backward direction (-z)
        {
          theParticleGun->SetParticleMomentumDirection(G4ThreeVector(0.0, 0.0, -1.0));
          // set the polarization
          setOptPhotonPolar(90.0);
          // generate the particle
          theParticleGun->GeneratePrimaryVertex(myEvent);
        }
      }  // end looop over both beam directions
    }    // end looop over particles in beam
  }      // end loop over beams
}

setOptPhotonPolar()

void LaserBeamsBarrel::setOptPhotonPolar

(

G4double

Angle

)

set the polarisation of the photons

Definition at line 159 of file LaserBeamsBarrel.cc.

References funct::cos(), funct::sin(), mathSSE::sqrt(), and theParticleGun.

Referenced by GeneratePrimaries(), and LaserBeamsBarrel().

                                                       {
  /* *********************************************************************** */
  /*   to get optical processes working properly, you have to make sure      *
   *   that the photon polarisation is defined.                              */
  /* *********************************************************************** */

  // first check if we have an optical photon
  if (theParticleGun->GetParticleDefinition()->GetParticleName() != "opticalphoton") {
    edm::LogWarning("SimLaserAlignment:LaserBeamsBarrel")
        << "<LaserBeamsBarrel::setOptPhotonPolar()>: WARNING! The ParticleGun "
           "is not an optical photon";
    return;
  }

  //   G4cout << "  AC1CMS: The ParticleGun is an " <<
  //   theParticleGun->GetParticleDefinition()->GetParticleName();
  G4ThreeVector normal(1.0, 0.0, 0.0);
  G4ThreeVector kphoton = theParticleGun->GetParticleMomentumDirection();
  G4ThreeVector product = normal.cross(kphoton);
  G4double modul2 = product * product;

  G4ThreeVector e_perpendicular(0.0, 0.0, 1.0);

  if (modul2 > 0.0) {
    e_perpendicular = (1.0 / sqrt(modul2)) * product;
  }

  G4ThreeVector e_parallel = e_perpendicular.cross(kphoton);

  G4ThreeVector polar = cos(Angle) * e_parallel + sin(Angle) * e_perpendicular;

  //   G4cout << ", the polarization = " << polar << G4endl;
  theParticleGun->SetParticlePolarization(polar);
}

Member Data Documentation

theDRand48Engine

CLHEP::DRand48Engine* LaserBeamsBarrel::theDRand48Engine

private

Definition at line 45 of file LaserBeamsBarrel.h.

Referenced by GeneratePrimaries(), LaserBeamsBarrel(), and ~LaserBeamsBarrel().

thenParticle

G4int LaserBeamsBarrel::thenParticle

private

Definition at line 38 of file LaserBeamsBarrel.h.

Referenced by GeneratePrimaries(), and LaserBeamsBarrel().

thenParticleInGun

G4int LaserBeamsBarrel::thenParticleInGun

private

Definition at line 37 of file LaserBeamsBarrel.h.

Referenced by LaserBeamsBarrel().

theParticleGun

G4ParticleGun* LaserBeamsBarrel::theParticleGun

private

Definition at line 42 of file LaserBeamsBarrel.h.

Referenced by GeneratePrimaries(), LaserBeamsBarrel(), setOptPhotonPolar(), and ~LaserBeamsBarrel().

thePhotonEnergy

G4double LaserBeamsBarrel::thePhotonEnergy

private

Definition at line 39 of file LaserBeamsBarrel.h.

Referenced by GeneratePrimaries(), and LaserBeamsBarrel().